Coating for paper



' Oct. 20, 1942. GREEN 2,299,693

COATING FOR PAPER Filed Feb. 25, 194 0 Barrett K. Green Inventor HisAttorney Patented Oct. 20, 1942 COATING FOR PAPER Barrett K. Green,

National Cash Register Company, Ohio, a corporation of Maryla awiDayton, Ohio, assignor to The Dayton,

Application February 23, 1940, Serial No. 320,385

19 Claims.

This invention relates to paper that is sensitizcd to produce visiblemarkings on its surface in response to impact or pressure.

The invention more particularly relates to an impact-sensitive emulsioncoating for paper, to be dried thereon, the dried coating havingprofusely dispersed at random therein minute liquidcontaining cells oftwo types, which two types of liquid are kept chemically insulated onefrom the other until the coating is ruptured in selected areas by impactor pressure, whereupon the liquid contents of the two types of cells arecaused to contact and chemically unite with one another to form alocalized stained area. The individual cells are so small and the effectof the rupturing of the coating is so localized that the mark left onsuch sensitized paper by being struck by type, for instance, appears tothe eye as ordinary printing, the individual contents of the rupturedcells causing a mosaic effect.

Therefore, it is the principal object of this invention to provide asensitized paper that will generate a visible mark where struck.

Another object of the invention is to provide a coating for paper which,when applied, sensitizes the paper to impact or pressure to produce alocal visible mark.

Another object of the invention is to provide a coating for paper whichis a mixture of two emulsions having the same continuous phase butdifferent discontinuous phases, which discontinuous phases arechemically active with one another on contact, but which are normallychemically insulated one from the other by the continuous phase.

Another object of the invention is to provide paper having a coatingconsisting of a plurality of types of liquid cells profusely dispersedin a plasticized solid, which solid is rupturable by impact to produce,at the place of rupture, a visible stain caused by chemical combinationof the liquids from difierent cell types.

Another object of the invention is to produce a solid film containing aprofuse number of discrete liquid cells, invisible to the unaided eye,that are rupturable by an impact to produce, by means of the releasedliquids, a local visually integrated area.

Another object of the invention is to provide an emulsion having thesame continuous phase and a plurality of discontinuous phases, thecontinuous phase of which may be dried into a tough transparent filmhaving dispersed therein liquid cells formed from the discontinuousphases of the emulsion.

With these and incidental objects in view. the invention includescertain novel features of construction and combinations of parts, the essential elements of which are set forth in appended claims and apreferred form or embodiment of which is hereinafter described withreference to the drawing which accompanies and forms a part of thisspecification.

The drawing is a diagrammatic cross-section through a coated piece ofpaper showing the dried coating thereon, and showing a typical rupturethereof.

GENERAL DESCRIPTION In preparing the coating, two emulsions are made,the continuous phase of each emulsion being the same solution of a solidand a liquid drying agent. The dispersed phase of each emulsion isselected so as to be chemically reactive on contact with the dispersedphase of the other emulsion to produce a stain. The emulsions soprepared are then applied to the paper either by mixing them togetherand applying the mixture or by applying one emulsion followed by theother after a short drying period. The common continuous phase of theemulsion is selected so that it chemically insulates the interspersedchemically active discontinuous phases of the mixture of emulsionsagainst reaction during normal handling while the mixture is in theliquid state. If the emulsions are applied separately, the secondemulsion combines with the first-applied emulsion to a depth determinedby the time the first emulsion is allowed to dry, as the commoncontinuous phase of the emulsions allows the second-applied emulsion topenetrate the partially-dried first coat.

The common continuous phase of the emulsions is preferably colorless andtransparent, as are the two types of liquids dispersed in the continuousphase, as it is desirable to have the backgrond color of the paper showthrough. However, it is within the scope of this invention to have thecontinuous phase or either of the discontinuous phases of the emulsionof some characteristic color to contrast with the color produced by theimpact or pressure.

As the coating produced must be flexible and indifferent to ordinarychanges in temperature and humidity, plasticizers and hygroscopiccontrol substances may be included in the coating.

A protective coating of wax, gum, or other inert film may be placed overthe emulsion coating as a protection against damage by friction,pressure, or special atmospheric conditions.

EMULSION #1 Continuous phase Grams 1:1 solution of gum dammar in toluene100 Di-( para tert-butylphenyl) mono-phenyl phosphate (C26H3104P), as aplasticizer 8.5

Discontinuous phase Grams Glycerine 33 Ferric ammonium sulphate 3.2Water 14 EMULSION #2 Continuous phase Same as the continuous phase ofEmulsion #1.

Discontinuous phase Glycerine grams 33 Gallic acid d 6.4 Water do 14 Theapproximate analysis of the dried coating produced by mixing the abovetwo emulsions and applying the mixture to the paper is:

Continuous solid phase Percent Gum dammar 52.0 Di-(paratert-butylphenyl) mono-phenyl phosphate 8.9

Discontinuous or dispersed phase Percent Glycerine 33.8

Ferric ammonium sulphate 1.7

Gallic acid; 3.6

The emulsions are so made as to cause the dispersed cells to be of asize under 1 millimeter in diameter, which result may be obtained by theuse of a screen of 325 mesh to the inch. The dispersed cells of suchminute size produce, when a great number of them are ruptured, stainsthat appear continuous to the eye even though the stain is composed of agreat number of smaller stain areas.

The coating may be applied so as to leave the dispersed cells only onedeep or several deep over the surface of the paper, depending on thetype of impact or pressure which the paper is to receive, or on theresults desired. It is obvious that, by use of a different selection ofstain-producing chemicals in the dispersed phases of the coating, almostany color of stain can be produced.

Various plasticizers such as castor oil, tri-butyl phosphate, or butylstearate may be used in appropriate quantities in place of the di-( paratertbutylphenyl) mono-phenyl phosphate.

The plasticized solids used as the continuous phase of the coating maybe selected for the characteristics of flexibility desired withoutdeparting from the spirit of the invention.

Referring to the drawing, the dispersed liquid cells of Emulsion #1 andthe dispersed liquid cells 2| of Emulsion #2 are shown imbe-dded atrandom in the solid continuous phase 23 of the coating 24. When thecoating is ruptured internally by the bursting of the cells, as at point22, the cells 20 and 2| have their contents combined, as at 25,producing a staining compound which contrasts with the color of thepaper 26. In the case of the two formulas given, the compound resultingfrom the reaction of the gallic acid and the ferric ammonium sulphate isof a blue-black color changing to a black color.

The scope of the invention is not deemed to be limited to a coating ofthe particular substances contained in the emulsion given as an example,but is deemed to cover any rupturable coating containing dispersedinclusions of heterogeneous liquids having a local stain-producingaction when caused to contact by rupture of the continuous phase of thecoating.

While the form of invention herein shown and described is admirablyadapted to fulfill the objects primarily stated, it is to be understoodthat it is not intended to confine the invention to the form orembodiment herein disclosed, for it is susceptible of embodiment invarious forms all coming within the scope of the claims which follow.

What is claimed is:

1. A liquid emulsion having a continuous phase which is a solution of asolid in a drying liquid, and having a plurality of chemically reactivediscontinuous phases, said continuous phase upon drying becoming arupturable solid continuous phase having dispersed therein heterogeneousliquid inclusions formed from the said discontinuuous phases and saidliquid inclusions being reactive to form a stain when allowed to mixupon the rupture of the solid phase.

2. An emulsion having a continuous phase and two discontinuous phases,said discontinuous phases each being colorless but chemically reactiveto form a stain if physically in contact. but which are kept fromcontact with one another by the continuous phase until said continuousphase is broken.

3. An emulsion having a continuous phase and a plurality ofheterogeneous discontinuous phases which are chemically reactive oncontact to form a perceptible mark but are physically separated by thesaid continuous phase under normal conditions which do not rupture thecontinuous phase.

4. A rupturable solid film having profusely dispersed at random thereintwo types of liquidcontaining cells of microscopic size, the liquids ofthe two types of cells being chemically reactive to produce a stain butnormally physically separated by the solid until the solid is ruptured.

5. A solid film having profusely dispersed at random therein two typesof discrete liquid-containing cells invisible to the unaided eye, saidsolid being rupturable by pressure to cause the contents of saidruptured cells to coalesce locally and react chemically so as to becomevisible.

6. The combination with a paper body, of a rupturable cellular coatingthereon, the cells of said coating being profusely dispersed at randomthroughout the coating and containing colorless liquids which, whenallowed to coalesce upon rupture of the coating, combine to produce astain.

7. The combination with a paper body, of a coating comprising a plasticsolid having profusely dispersed at random therein a plurality of kindsof liquid inclusions, said coating being resistant to ordinary handlingbut rupturable by printing impacts to coalesce the different kinds ofliquid inclusions at the points oi impact, which coalesced liquids reactto term a perceptible mark within the coating.

8. A coating for paper consisting of a plastic solid having profuselydispersed therein heterhaving dispersed therein Grams, Glycerine 33Ferric ammonium sulphate-.. 3.2 Water 14 and the second of saidemulsions being:

Grams lzl'solution of gum dammar in toluene 100 Di-(paratert-butylphenyl) mono-phenyl.

phosphate (CaeHsxOsPl 8.5 having dispersed therein Grams Glycerine 33Gallic a 6.4 Water 14 both or said dispersed phases having a particlesize of less than .1 millimeter in diameter.

phases being normally isolated from each other by the continuous phasebut being chemically reactive to roduce a stain when the continuousphase is broken down to allow them to contact with one another. y

13. A solid having dispersed at random therein discrete inclusions ofchemically heterogeneous liquids, said solid having been derived from acontinuous phase oi an emulsion by drying and the liquid inclusionshaving been-the discontinuous phases of said emulsion. I

14. A liquid coating compositioii comprising an emulsion having acontinuous phase and a plurality oi discontinuous chemically reactivephases. said emulsion being converted by drying into a rupturable solidcontinuous phase containing a plurality of liquid discontinuous phaseswhich react to form a stain when they coalesce upon rupture oi the solidphase.

15. A sensitized record material comprising a base sheet having acoating of aplastic solid containing profusely distributed at randomtherein discrete inclusions oi liquids which are chemically reactive toform a visible mark, said coating being resistant to rupture in ordinaryhandling but rupturable by printing impacts to coalesce 10. The methodof sensitizing paper to produce I visible marks by impact comprising thesteps of applying a first coating consisting of an emulsion having adryable continuous phase and a discontinuous phase'which remains asliquid inclusions in the dried continuous phase, and the step ofapplying a second coating over the first coating as said first coatinghas partially dried, said second coating being an emulsion having thesame kind of continuous phase as the first coating and a discontinuousphase of a substance chemically reactive to the substance of thediscontinuous phase of the first coating, the two mentioneddiscontinuous phases being partially interspersed in the coating butchemically separated by a common continuous phase.

11. The method of sensitizing paper to produce visible marks by impactcomprising the steps of preparing a first emulsion having a dryable liq-'uid continuous phase and a discontinuous phase of a rupturable solidcont the liquid inclusions and enable the chemical reactign to formvisible marks at the points of impac 16. A sensitized record materialcomprising a base sheet having thereo a coating composed uous phase andcontaining a profusion of interspersed droplets of a plurality ofdiscontinuous liquid phases which liquid phase are chemically reactiveto produce a stain within the coating when allowed to coalesce uponrupture oi the continuous phase.

17. A sensitized record material comprising a base sheet having thereona coating composed of a rupturable plastic continuous phase containingprofusely dispersed therein microscopic discrete liquor inclusions oiaplurality of chemically reactive substances which react to form avisible mark when allowed to coalesce and which are normally separatedby the continuous phase but are released by the rupture of thecontinuous phase and react to form a visible mark at'the point ofrupture.

18. A sensitized record material comprising a base sheet having thereona coating composed of a rupturable plastic solid continuous phase whichhas profusely dispersed therein droplets of two discontinuous liquidphases which react to form a stain when allowed to coalesce by ruptureof the plastic solid.

/ 19. Asensitized record material comprising a base sheet having thereona colorless, transparent coating comprising a rupturable solid phasecontaining a profusion of discrete liquid inclusions of a plurality ofdiscontinuous phases, the liquid in each of said discontinuous phasesbeing clear ,and colorless while contained in the discrete inclusionsbut being chemically reactive to form a visible colored mark whenallowed to coalesce upon rupture of the solid phase.

BARRE'I'I K. GREEN.

and two discontinuous phases, said discontinuous fi-sert. "finch forms aruptnrable solid phase- .icnnna'icn'm or connscmion.

' October 20;, 191 2.

It in: hereby certified that error appea rsin the printed specificationof the above mnnbered patent re qui'rin'g correction as follows: Page 5,first column, line 11., claim 8, for "A coating for paper consisting of"read The combination witnpeper, of'a coating compris1ng--; line 12,claim 9, after coating insert material.--; line k0, claim 10, before"and" inijo'r the words "a-common continuous" read -the commonrupturable contin ii ioufl"; line 66, claim 11, after "phase" and beforethe periddinsert --'-to Ibnn a. m pturable solid coating containingprofusely interspersed discrete inclusions of the two chemicallyreactive discontinuous phases--- li d seoond co umn, line '1, claim 12after "phases" and before the comma insert firofdsel'y'dispersdtherein-q line 2, same claim, afte i insert niicroscopicdroplets--; lines 7,8 and 9 claim 15 for solid havingdispersed atrandom. therein discrete inclusions oichemic'ally heterogeneous liquids,saidsolid" read --A solid film having discrete incl lesions ofchemically heterogeneous liquids profusely dispersedat random throughoutit, said film-: line 16, claim 11;, for "converted? read "co vertible-.line #5, claim 17, for "'liquor" read -liquid-; and tha t th'e' saidLetters Patent should be read with this correction therein that the samemay conform to the record of the case in the Patent Office.

Signed and sealed this 21pm day of November, A. D. lgiia.

Henry Van Arsdale,

"( 1) Acting Commissioner of Patents.-

lines51and 52, same claim,

. cert. which forms a r'uptfirable solid phaseicsRmrIcAm or commcnon.

--Pate nt no; 2,299,693. October 20, v151;.2.

of the above 'cnumbered patent requiring column, line 14., claim 8, 4read 5 m n fi thps per, cf a ccating comprising--; line 12, claim 9,after "coatin'g' insert -me.teria1,--; line #0, claim 16, before "and"inlines 51 and 52, same claim, {or the words "acommon continuous read--the common rupturable continficus; line, 66, claim- 11, after "phase"and before the period insert iend second column, line 1, claim 12, after"thases and before the comma insert profusely dispersed-therein-'; line2, same claim, after "bein insert n iicroscbpic droplets; lines 7, 8 and9 claim f r having dispersed at random therein discrete inclusions of.chemically heter- 'ogeneous liquids, sa id'solid' read I out it, saidfilm-E; line 16, claim 11+, for "converted" read "convertible--;' 111161claim 17, for "'liquor" read ---liquid-; and the tithe said LettersPatent sheuld be read with this correction therein that the same mayconform to the record of the case in the Patent Office.

Signed ma sealed this 2mm da of November, A. n. 19u2.

Hem-y va Arsdale,

( Acting Connnissioner of Patents.

Page 5, first ."A solid film having discrete incltlsions of chemicallyheteregeneeus liquids 'promsel-y dispersed-at random thrcugh-

